Enzymatic Formation of Testololactone^*

Abstract

tion were spotted upon Vaseline-impregnated Whatman No. 1 paper and chromatographed. They gave zonea with RP values of 0.25, 0.18, and 0.19, reapectively. Catrrlytic Hydrogenation of an Origid Prepamtion of Vitamin K from M. phlei.-A 2.4-mg sample of an original preparation from M. p?&i was catalytically hydrogenated.A sample of the product, in the quinone form, equivalent to 300 pg of the preparation before reduction, was spotted upon Vaseline-impregnated Whatman No. 1 paper. samples of the correeponding products from vitamin Ko(H) and Kt(M) were also placed upon the paper. The paper chromatogram was developed (descending) for 13 days with glacial acetic acid saturated with Vaseline as solvent. A mixture of the vitamin Kzcw, and Ko(H) reduction produds gave zones 3.6 cm and 7.4 cm, respectively, from the origin.The product from the original preparatidn from M. phlei gave a slightly elongated zone 7.0 cm from the origin.

Baeyer–Villiger oxidation of some steroids by Aspergillus tamarii MRC 72400

“…After 24 h, the presence of the 18-methyl signal of testosterone (3) shifted from 0.77 to 1.37 ppm and further comparison of the methyl group integrations in the 1 H NMR spectrum indicated that 100% of androst-4-ene-3,17-dione (12) had been converted to testolactone (9). Further comparison of the methyl group integrations in the 1 H NMR spectra suggested that no more reactions took place after 48 h. Time course experiment indicated that testosterone (3) was first converted to androst-4-ene-3,17-dione (12) and this compound was then converted to testolactone (9) by a BVMO activity (Scheme 1) as it was in the incubation of this substrate with Penicillium lilacinum 30 . A. tamarii QM 1223 showed the same activities accompanied by an independent minor 11β-hydroxylation pathway and the yield 17 of 9 was lower than that from A. tamarii MRC 72400.…”

A Fascination with Enzymes: The Journey Not the Arrival Matters

“…Isotope incorporation and exchange experiments with 18 O 2 and H 2 18 O established that the oxygen atom linking C-13 and C-17 in the six-membered D ring of the steroid lactone was derived from molecular oxygen. The lactonase mechanism was therefore formally similar to the BaeyerVilliger oxidation of cyclic ketones to lactones by peracids (22).…”

Monooxygenase-Mediated Baeyer−Villiger Oxidations

“…The BVMO responsible was dependent on molecular oxygen, as was demonstrated for a partially purified enzyme preparation. [33] Initial structure acceptance studies revealed significantly different substrate profiles for steroid monooxygenases. [34] A BVMO from C. radicicola was purified by affinity chromatography and oxidatively cleaved the side chains of several steroidal structures.…”